Brussels sprouts make waves

Jul 11 2012

Kim Juniper: back to the drawing board.

Kim Juniper learned a number of lessons during this summer's scientific expedition to deep reaches of ocean, 200 kilometres off the coast of Vancouver Island.

For example, fibre-optic cable is extremely fragile and brussels sprouts are a better choice than extra cable when weight is limited.

"I thought the cable was nice to have, but the sprouts might be the only vegetable we were going to get," said Juniper, chief scientist on the second leg of a month-long expedition that aimed to hook an array of tsunami sensors into the NEPTUNE (North-East Pacific Timeseries Undersea Networked Experiments Canada) cabled ocean observatory.

The sprouts were a sensible choice as much of the fibre-optic cable turned out to be not strong enough to withstand the stress of being laid along the sea floor by a remotely operated vehicle.

"We spent two days laying it along the sea floor and then tested it and it didn't work," Juniper said. "It was frustrating."

Now it's back to the drawing board - and to the cable manufacturer - to find a fibre-optic cable skinny enough to be carried by the ROV, but tough enough to withstand the rigours of the deep ocean.

The aim is to have another incarnation of cable ready before the next cruise in late September.

NEPTUNE streams realtime data from an 800-kilometre loop of fibre-optic cable under the Pacific Ocean to scientists and students all over the world.

NEPTUNE and VENUS (the Victoria Experimental Network Under the Sea, which keeps its fibre-optic eyes on Saanich Inlet), are managed by Oceans Networks Canada and led by the University of Victoria.

The aim of the expedition was to set up a star-shaped array of deep-sea tsunami sensors, with fibre-optic cable arms stretching 20 to 25 kilometres at a depth of about 2,700 metres.

The array will allow scientists to research the strength and direction of tsunami waves.

"The whole goal is to allow better models of how tsunamis approach our coast from distant sources," Juniper said.

Once the highly sensitive sensor arrays and bottom pressure recorders are hooked to the NEPTUNE central node, they will provide data to the Pacific Tsunami Warning Network and could give Vancouver Islanders a 30-minute warning of a tsunami.

In the meantime, individual, battery-operated sensors are continuing to provide information.

"They are the most sensitive ocean pressure sensors in the world," Juniper said. "But we don't have that wonderful big array on line. Yet."

Meanwhile, NEPTUNE may be expanding its undersea watch to the Arctic.

Kate Moran, president of Ocean Networks Canada, said a prototype observatory could be installed in the Arctic this summer.

"We want to begin to make more observations in the Arctic because that ocean is at extreme risk because of climate change," she said.